Multifunctional Composite Material with Efficient Microwave Absorption and Ultra-High Thermal Conductivity

The increasing demands for electronic devices to achieve high miniaturization, functional integration, and wide bandwidth will exacerbate the heat generation and electromagnetic interference, which hinders the further development of electronic devices. Therefore, both the issues of microwave absorption and heat dissipation of materials need to be addressed simultaneously. Herein, a multifunctional composite material is proposed by periodic arrangement of copper pillars in a matrix, based on the wave-absorbing material. As a result, the equivalent thermal conductivity of the composite structure is nearly 35 times higher than the wave-absorbing matrix, with the area filling proportion of the thermal conductivity material being 3.14%. Meanwhile, the reflectivity of the composite structure merely changes from −15.05 dB to −13.70 dB. It is proved that the designed composite structure possesses both high thermal conduction and strong microwave absorption. The measured results accord well with the simulation results, which demonstrates that the thermal conductivity of the composite structure can reach more than 10W⋅m −1 ⋅K −1 without significant deterioration of the absorption performance.